Tumors and Cysts

Slide 1 · Tumors and Cysts

Fallopian tube pathology

Paratubal cysts • Adenomatoid tumor • Tubal serous precursors

Dr Abu Suraih Sakhri

MBBS, MD (Pathology)

www.abusuraihsakhri.com

Slide 2 · Learning objectives

Recognize the characteristic features of paratubal cysts and hydatids of Morgagni.

Localize adenomatoid tumors and distinguish them from cystic lesions.

Explain the evidence linking tubal epithelium, STIC, and high-grade serous carcinoma.

Apply the tubal-origin model to clinicopathologic interpretation.

Slide 3 · The fallopian tube is the anatomical focus

Simplified topography — schematic, not a specimen

Uterine end

Tube

Fimbriae

Ovary

Mesosalpinx / broad ligament

Paratubal site

Tubal epithelial origin ↔ ovarian involvement are distinct sites

Slide 4 · Three lesion categories frame this topic

01

Paratubal cysts

Common, benign, serous-fluid lesions.

02

Adenomatoid tumors

Uncommon benign tubal or mesosalpinx nodules.

03

Tubal serous precursors

Clinically important in high-grade serous carcinogenesis.

Slide 5 · “Tubal mass” does not imply one diagnosis

01

Cyst vs. Nodule

A cystic paratubal lesion and a subserosal solid nodule are different entities.

02

In situ vs. Benign

An intraepithelial precursor is not equivalent to a benign cyst.

03

Diagnostic dimensions

Location, architecture, and biologic potential must be considered separately.

Slide 6 · Fallopian tube disorders: The broader context

Inflammation and infection are frequent tubal disorders.

Ectopic pregnancy and endometriosis are other important tubal pathologies.

This lecture concentrates on cysts, benign tumors, and serous neoplastic origin.

Slide 7 · Inflammation remains a separate disease category

Inflammation

Cysts / tumors

Suppurative salpingitis is part of pelvic inflammatory disease.

The supplied text identifies gonococci and chlamydiae among key causative organisms.

Inflammatory tubal lesions should not be classified as paratubal cysts or tumors.

Slide 8 · Tubal tuberculosis: Why context matters

Tuberculous salpingitis is uncommon in the United States.

Its greater relevance where tuberculosis is prevalent.

Infertility is an important clinical consequence in high-prevalence settings.

Slide 9 · Structure and behavior are independent axes

Anatomic location

Structure

Behavior

Cystic versus nodular describes gross form.

Benign, in situ, and invasive describe biological categories.

Neither axis alone establishes the exact site of origin.

Slide 10 · Paratubal cysts are the common primary lesions

Paratubal cysts as the most common primary tubal lesions when endometriosis is excluded.

Their prevalence relative to other tubal tumors is qualitative in this excerpt.

They are generally of little clinical significance.

Slide 11 · Typical size: 0.1–2 cm

0.1–2 cm

The source describes minute lesions within this size range.

Size is a gross descriptor, not by itself a malignancy criterion.

Larger named examples are discussed separately as hydatids of Morgagni.

Slide 12 · Translucency is a macroscopic clue

Schematic cyst

Paratubal cysts are described as translucent.

The appearance is consistent with their clear serous contents.

Gross translucency does not establish the microscopic lining by itself.

Slide 13 · The cyst lumen contains clear serous fluid

Lumen / epithelial boundary

Schematic only

The fluid is specifically described as clear and serous.

The cavity is epithelial-lined rather than solid.

Fluid character should be integrated with site and epithelial morphology.

Slide 14 · Lining epithelium is benign and tubal-type

Conceptual epithelial lining (not an H&E section)

Benign tubal-type epithelium

The source describes benign serous (tubal-type) epithelium.

Slide 15 · Müllerian remnants are the presumed origin

Paratubal cysts are presumed to arise from remnants of the Müllerian duct.

“Presumed” signals a proposed developmental origin.

Do not treat a presumed origin as directly demonstrated for every cyst.

Conceptual relationship; Arrows are schematic, not measured progression

Slide 16 · Localization: Beside rather than within ovary

Simplified topography — schematic, not a specimen

Uterine end

Tube

Fimbriae

Ovary

Mesosalpinx / broad ligament

Paratubal site

Tubal epithelial origin ↔ ovarian involvement are distinct sites

Slide 17 · Hydatids of Morgagni: The named variant

Schematic cyst

The text uses this term for larger cysts near the fimbrial end or broad ligaments.

They belong to the same benign tubal-type cyst spectrum.

The terminology is an anatomical and gross-pathologic descriptor.

Slide 18 · Paratubal cyst versus hydatid of Morgagni

Paratubal cyst

Hydatid of Morgagni

Paratubal cyst: The general common cystic lesion.

Hydatid of Morgagni: A larger example in a characteristic location.

Both are described with benign serous/tubal-type epithelium.

Slide 19 · Gross and microscopic descriptions complement one another

Gross: Small, translucent, clear-fluid cavity.

Microscopy: Benign serous/tubal-type epithelial lining.

Interpretation: A lesion of little significance description.

Conceptual relationship; Arrows are schematic, not measured progression

Slide 20 · A benign cyst is not a serous carcinoma precursor by default

Paratubal cyst

Serous tubal in situ lesion

A paratubal cyst is presented as benign.

STIC is a distinct intraepithelial neoplastic lesion associated with serous carcinoma.

The excerpt does not claim that paratubal cysts progress to STIC.

Slide 21 · What the cyst description can establish

Cystic architecture and a benign tubal-type lining support the cyst diagnosis.

The described lesion is not characterized by invasive growth.

The source does not prescribe a marker panel or quantitative diagnostic cutoff.

Slide 22 · What the cyst description cannot establish

Translucency alone cannot prove site of origin.

The source does not define diagnostic sensitivity for gross appearance.

No malignancy risk estimate is supplied for an otherwise typical cyst.

Slide 23 · Case 1: An incidental translucent adnexal cyst

Diagnostic application

A small, clear-fluid cyst is encountered adjacent to the tube.

The epithelial lining is benign and tubal-type.

Which entity best fits the source description, and why?

Slide 24 · Case 1: Lesion-level interpretation

Favored diagnosis: Paratubal cyst.

Support: Location, minute translucent cavity, clear serous fluid, benign tubal lining.

Do not infer malignant potential from the word “serous” alone.

Slide 25 · Benign tubal neoplasms are rare

Robbins explicitly describes benign tumors of the tube as rare.

Adenomatoid tumor is the example named in this passage.

Frequency is not quantified in the provided section.

Slide 26 · Adenomatoid tumor: An uncommon benign nodule

Small subserosal nodule

The tubal lesion is described as a small nodule.

It is a benign tumor, not one of the common paratubal serous cysts.

Its anatomical relation to the tubal serosa is central in this source.

Slide 27 · Subserosal tubal localization

Tubal lumen

Tubal wall

Outer serosal plane

Nearby mesosalpinx

Adenomatoid tumor may occur beneath the serosa of the tube.

Subserosal localization is a tissue-plane descriptor.

Location must be distinguished from the tubal epithelial lumen.

Slide 28 · The mesosalpinx is an alternative site

Simplified topography — schematic, not a specimen

Uterine end

Tube

Fimbriae

Ovary

Mesosalpinx / broad ligament

Paratubal site

Tubal epithelial origin ↔ ovarian involvement are distinct sites

Slide 29 · Tubal and male genital counterparts

Fallopian tube / mesosalpinx

Testis / epididymis

The source identifies counterparts in the testis and epididymis.

This is a cross-organ comparison of the same named benign tumor.

The excerpt does not describe a hereditary or metastatic relationship.

Slide 30 · Cyst versus adenomatoid nodule

Fluid-filled cyst

Subserosal nodule

Paratubal cyst: Translucent, fluid-filled, epithelial-lined cavity.

Adenomatoid tumor: Small benign subserosal or mesosalpinx nodule.

Gross form and tissue plane distinguish the two concepts.

Slide 31 · A solid nodule demands a different question

First: Anatomical and morphologic localization

Confirm whether the lesion is in tubal wall or mesosalpinx.

Assess whether the description is cystic or nodular.

Do not assign a cyst diagnosis without epithelial-lined cyst architecture.

Slide 32 · Case 2: Small subserosal tubal nodule

Diagnostic application

A small discrete nodule is identified beneath tubal serosa.

No serous-fluid cavity is described.

Which benign tumor is specifically named by Robbins at this location?

Slide 33 · Case 2: Localize before naming

Adenomatoid tumor is the named benign tubal nodule.

Subserosal location fits the source description.

This is not evidence of a paratubal cyst or an intraepithelial serous carcinoma.

Slide 34 · The major malignant insight is anatomical

Historically, primary fallopian tube carcinoma was regarded as rare.

That many “ovarian” serous carcinomas actually originate in tubal epithelium.

The conceptual change concerns site of origin, not merely renaming the cancer.

Slide 35 · Why the ovarian label can be misleading

A carcinoma may present with an ovarian or pelvic mass.

The initiating epithelial lesion may nevertheless have arisen in the tube.

Tumor distribution at presentation does not always identify its initiating site.

Conceptual relationship; Arrows are schematic, not measured progression

Slide 36 · Fimbriae are central to the proposed pathway

Simplified topography — schematic, not a specimen

Uterine end

Tube

Fimbriae

Ovary

Mesosalpinx / broad ligament

Paratubal site

Tubal epithelial origin ↔ ovarian involvement are distinct sites

Slide 37 · STIC is an intraepithelial carcinoma

Conceptual epithelial lining (not an H&E section)

Atypical epithelium — simplified STIC concept

STIC means serous tubal intraepithelial carcinoma.

Slide 38 · STIC: The atypical epithelial precursor

Marked epithelial atypia was observed in risk-reducing fallopian tubes.

These lesions were termed STIC.

The observation prompted reconsideration of the origin of high-grade serous carcinoma.

Slide 39 · Observation 1: STIC in genetically high-risk tubes

STIC was identified during prophylactic salpingo-oophorectomy in BRCA1/2 germline mutation carriers.

This observation as an origin-of-cancer clue.

A precursor at a proposed primary site provides anatomically relevant evidence.

Slide 40 · Observation 2: STIC with sporadic serous cancer

STIC lesions have also been described alongside sporadic high-grade serous carcinomas.

This extends the tubal-origin hypothesis beyond inherited-risk cases.

Association supports, but does not prove, the origin of every individual carcinoma.

Slide 41 · Observation 3: Residual risk when tubes remain

The passage associates omission of tubal removal at oophorectomy with residual “ovarian” cancer risk.

This supports the clinical relevance of the fallopian tube.

The excerpt does not provide a patient-level risk estimate for this comparison.

Slide 42 · Converging lines of evidence

01

Anatomy

Epithelial atypia at the fimbrial site.

02

Pathology

STIC associated with high-grade serous carcinoma.

03

Clinical observation

Cancer risk persists if fallopian tubes are left in place.

Slide 43 · Source-supported tubal-origin pathway

Tubal fimbrial epithelium

STIC precursor

High-grade serous carcinoma

Ovary / peritoneum

Invasive disease can involve ovary and peritoneal surfaces.

Slide 44 · A proposed origin is not the whole clinical distribution

The presumed initiating tissue and the site of a large tumor mass may differ.

Many high-grade serous tumors are widely distributed when detected.

Nomenclature must not obscure the origin-versus-spread distinction.

Conceptual relationship; Arrows are schematic, not measured progression

Slide 45 · Peritoneal dissemination fits the tubal model

Tubal origin

Exfoliation

Peritoneal seeding

Disseminated disease

A peritoneal pattern of disease is therefore compatible with tubal origin.

Slide 46 · Not every high-grade serous tumor has visible STIC

Tubal precursor pathway

Alternative ovarian hypothesis

The exact fraction of sporadic tumors of tubal origin is unknown.

An ovarian inclusion-cyst pathway has also been proposed.

Absence of a documented STIC does not settle the origin in an individual case.

Slide 47 · The ovarian inclusion-cyst hypothesis

Cortical inclusion cysts were historically proposed as a source of serous cancers.

A newer interpretation considers implantation of detached tubal epithelium onto ovulation-disrupted ovary.

The source presents these as explanatory hypotheses, not definitive mechanisms in all patients.

Conceptual relationship; Arrows are schematic, not measured progression

Slide 48 · Two concepts should not be conflated

01

Distinct cyst sites

A benign paratubal cyst is not the same lesion as an ovarian cortical inclusion cyst.

02

Tubal precursor

STIC is a neoplastic tubal epithelial precursor.

03

Precise nomenclature

Different sites and biological contexts require separate labels.

Slide 49 · Inherited susceptibility provides biological context

Germline BRCA1 or BRCA2 mutations increase susceptibility to ovarian and breast cancer.

Hereditary-risk observations helped reveal tubal STIC lesions.

A susceptibility genotype is not itself proof of a visible precursor.

Conceptual relationship; Arrows are schematic, not measured progression

Slide 50 · High-grade serous carcinoma: Molecular profile

Origin / precursor

A high frequency of TP53 mutations.

Alterations

High-grade tumors generally lack KRAS or BRAF mutations.

Interpretation

Genomic imbalances are frequent, including oncogene gains and tumor-suppressor losses.

Slide 51 · Low-grade serous carcinoma is a different pathway

Origin / precursor

Low-grade tumors may arise from serous borderline tumors.

Alterations

KRAS, BRAF, or ERBB2 alterations are described.

Interpretation

TP53 mutations usually are not found in the low-grade pathway.

Slide 52 · Low-grade versus high-grade: Preserve the distinction

Low-grade serous

High-grade serous

Low-grade pathway: Borderline precursor; KRAS/BRAF/ERBB2; Relatively less aggressive course.

High-grade pathway: Often fimbrial STIC; Frequent TP53 alteration; Aggressive dissemination.

These are distinct models, not successive grades in one obligatory sequence.

Slide 53 · Why “serous” alone is insufficient

Anatomic location

Structure

Behavior

Serous describes fluid or epithelial differentiation in different contexts.

Benign paratubal cyst, low-grade carcinoma, and high-grade carcinoma are not interchangeable.

Biologic category must be added to descriptive terminology.

Slide 54 · Tubal removal entered cancer-prevention thinking

Implications for surgical risk reduction

The tubal-origin model changed the rationale for surgery in high-risk individuals.

Risk-reducing salpingo-oophorectomy in BRCA-associated susceptibility.

Salpingectomy alone has also been increasingly considered for risk reduction.

Slide 55 · An important prevention caveat

The full effect of salpingectomy-based risk reduction requires long-term observation.

The delay between intervention and typical cancer age.

The source does not supply a definitive prevention efficacy estimate.

Slide 56 · Case 3: Precursor found at risk-reducing surgery

Diagnostic application

A BRCA1 germline mutation carrier undergoes salpingo-oophorectomy.

A focus of marked epithelial atypia is identified within the fimbrial tube.

Which source-defined lesion provides a mechanistic link to high-grade serous carcinoma?

Slide 57 · Case 3: Interpret the precursor precisely

STIC is the source-defined intraepithelial serous carcinoma.

The finding supports the tubal-origin concept.

The case does not establish how frequently every sporadic cancer follows this pathway.

Slide 58 · A clinical localization matrix

01

Cystic lesion

Translucent clear-fluid cyst → consider paratubal cyst.

02

Nodular lesion

Small subserosal / mesosalpinx nodule → consider adenomatoid tumor.

03

Epithelial atypia

Atypical fimbrial intraepithelial lesion → consider STIC in the proper context.

Slide 59 · Three different meanings of “tubal”

Tubal lumen

Tubal wall

Outer serosal plane

Nearby mesosalpinx

Anatomical adjacency: A paratubal cyst lies beside the tube.

Organ wall: An adenomatoid tumor can be subserosal.

Cell of origin: High-grade serous carcinoma may arise from tubal epithelium.

Slide 60 · Morphology, not an anatomical shortcut

First: Anatomical and morphologic localization

Tubal or adnexal location alone is not diagnostic.

Cystic versus nodular versus epithelial atypia directs interpretation.

A fully supported diagnosis requires appropriate morphology and clinical context.

Slide 61 · Key diagnostic contrasts

01

Common benign cyst

Small, clear serous lumen, benign tubal lining.

02

Rare benign neoplasm

Adenomatoid subserosal / mesosalpinx nodule.

03

Malignant precursor

STIC in atypical tubal epithelium, often fimbrial.

Slide 62 · Question: Does serous fluid predict serous cancer?

Diagnostic application

A translucent cyst contains clear serous fluid.

The lining is benign tubal-type epithelium.

Can the adjective “serous” alone support a malignant diagnosis?

Slide 63 · Answer: Descriptive terms are not diagnoses

No. Serous fluid or differentiation does not by itself establish malignancy.

The source categorizes typical paratubal cysts as lesions of little significance.

STIC and invasive serous carcinoma require a separate neoplastic context.

Slide 64 · Question: Which lesion changes cancer-origin thinking?

Diagnostic application

A small benign paratubal cyst is removed incidentally.

A separate focus of marked fimbrial epithelial atypia is discovered.

Which finding is central to the tubal-origin model?

Slide 65 · Answer: Precursor location matters

The atypical intraepithelial fimbrial lesion—STIC—is the relevant finding.

The benign paratubal cyst is not a proposed STIC precursor in this source.

Avoid causal connections that Robbins does not support.

Slide 66 · Integrated synthesis: Benign to malignant concepts

01

Paratubal cysts

Paratubal cysts dominate the common primary benign lesion category.

02

Adenomatoid tumor

Adenomatoid tumors are rare, small, benign subserosal or mesosalpinx nodules.

03

Tubal STIC

STIC and the tubal epithelium reshape our understanding of high-grade serous carcinoma.

Slide 67 · Reading the source critically

The core tubal-cyst passage is brief and emphasizes qualitative morphology.

The adjacent serous-carcinoma section supplies the mechanistic extension.

No source figure or whole-slide pathology image is reproduced in this deck.

Slide 68 · Selected references

Robbins, Cotran & Kumar. Pathologic Basis of Disease. 11th ed. 2026. Chapter 22, p. 922: Fallopian Tubes; Tumors and Cysts.

Same chapter, pp. 924–925: Ovarian Tumors; Serous Tumors—pathogenesis and tubal origin.

Same chapter, pp. 925–926: STIC; low-/high-grade serous carcinoma; spread and clinical behavior.