In dermatopathology, there are several conditions which must be addressed emergently. While some conditions necessitate emergent intervention because of the pathology of the cutaneous manifestations, others require recognition of the underlying serious systemic conditions represented by the cutaneous signs and symptoms. In this part, we address rickettsial infections and eczema herpeticum as diseases which should be addressed immediately on presentation because of the seriousness and rapidity of progression of their pathology. Moreover, porphyria cutanea tarda, Birt–Hogg–Dubé syndrome, Muir–Torre syndrome, and acquired ochronosis may exemplify conditions where the cutaneous signs serve as warnings for severe systemic disease that may not be emergencies in isolation but can indicate rapid occult development of destructive and sometimes deadly noncutaneous pathology. The literature review was conducted using searches in PubMed and references to textbooks on the subjects.

In this review, we use the term epithelioid cell granuloma for granulomas that show focal collections of epithelioid histiocytes in the absence of additional changes such as acute inflammatory cells and altered collagen or foreign material. Giant cells, lymphocytes, and histiocytes are often seen in these granulomas. Various features are useful in recognizing the specific cause of an epithelioid cell granuloma and include coalescence or discreteness of granulomas, presence and type of necrosis, inclusion bodies within giant cells, and identification of organisms, but the arrangement of granulomas within the dermis may be the single most important feature. Leprosy shows well-circumscribed, oval, oblong, and curvilinear epithelioid cell granulomas in a perivascular and peri-appendageal location involving superficial and deep dermis with minimal interstitial spill. Cutaneous tuberculosis is recognized by a lichenoid granulomatous pattern comprising a dense upper dermal infiltrate with granulomas that impinge on the overlying acanthotic epidermis accompanied by more localized, nodular granulomas in the deep dermis. Sarcoidosis has closely huddled yet discrete granulomas that have a paucity of lymphocytes. Other patterns and clues include follicular/perifollicular granulomas in lichen scrofulosorum and granulomatous rosacea, prominent necrosis in lupus miliaris disseminatus faciei, branching granulomas with plasma cells in granulomatous secondary syphilis, granulomatous lobular panniculitis with vasculitis in erythema induratum, messy granulomas in cutaneous leishmaniasis, and granulomas extending to the muscles in granulomatous cheilitis/Melkersson–Rosenthal syndrome. Histopathological findings, in combination with clinical and laboratory information, can lead to a specific diagnosis in the majority of cases.

Suppurative granulomatous inflammation is a common histopathological reaction pattern that is encountered in the tropical countries including India. It occurs usually due to infective etiology and identification of the causative pathogen is crucial to initiate appropriate treatment. In this review article, we discuss about certain common and uncommon condition which may present with this reaction pattern.

Granulomatous disorders comprise a large family sharing the common histological denominator of granuloma formation. Collagenolytic or necrobiotic granuloma is one in which a granulomatous infiltrate develops around a central area of altered collagen and elastic fibers. The altered fibers exhibit new staining patterns, becoming either more basophilic which gives blue appearance (“blue granuloma”) or eosinophilic giving red appearance (“red granuloma”). Conditions which exhibit blue granuloma include granuloma annulare, Wegener's granulomatosis, and rheumatoid vasculitis, whereas red granulomas include necrobiosis lipoidica, necrobiosis xanthogranuloma, rheumatoid nodules, Churg-Strauss syndrome, and eosinophilic cellulitis (Well's syndrome).

Background: Dermal melanophages are a common histopathological finding in several inflammatory skin diseases and may be seen even in clinically normal-looking skin. Clinically hyperpigmented and hypopigmented conditions as well as nonpigmented lesions show melanophages which cannot always be correlated with the clinical appearance of the lesion biopsied. No literature exists to help assess the significance of dermal melanophages in inflammatory diseases and correlate their presence with the pathophysiology of the disease biopsied. Methodology: This is a retrospective study of 100 skin biopsies in patients with brown skin, which had mentioned dermal melanophages in the histopathological report. A simple-to-use semi-objective scale (score of 3–10) was used to assess the score of the dermal melanophages. This was done by a dermatopathologist who was blinded to the clinical and histopathological diagnoses. A correlation of the dermal melanophage score was attempted with the clinical/histological diagnoses and known pathogenesis of the diseases. Results: A variety of skin diseases were included in this study which could be broadly grouped into hypopigmented (10 cases, average scores 4), nonpigmented interface diseases (20 cases, average score 6.66), miscellaneous nonpigmented dermatosis (17 cases, average scores 5.3), and hyperpigmented (53). The hyperpigmented group was subdivided into those that were known to show predominantly epidermal melanin (13 cases, average score 4.58) and those who have predominantly dermal melanin following interface dermatitis (29 cases, average score 8.67) and dermal melanosis without interface dermatitis (11 cases, average score 6.18). Conclusions: This scale can be used to determine the significance of dermal melanophages in inflammatory skin diseases. Scores >6 suggest hyperpigmentary conditions due to the presence of dermal melanophages. Low scores of 3–5 are not significant and are seen in epidermal hypermelanoses, hypopigmented conditions, and other varied nonpigmented dermatoses.

Background: Onychomycosis can resemble other nail dystrophies and hence the clinical diagnosis should be supplemented with a laboratory diagnosis. Rapid diagnosis of onychomycosis is the necessary to initiate early therapy. In this study, the efficacy of Chicago Sky Blue (CSB) stain in comparison with that of routine potassium hydroxide (KOH) preparation in the diagnosis of onychomycosis was evaluated. Methods: A prospective study of 42 nails with a clinical diagnosis of distal lateral subungual onychomycosis. KOH mount followed by direct microscopic examination of the subungual debris was performed. This was followed by microscopic examination after addition of 1% CSB. Results were interpreted by two experienced dermatologists. Results: 18 (42.9%) nails showed KOH positivity and 37 (88.1%) were positive for CSB stain. Conclusions: CSB staining was more sensitive and was more accurate in the rapid diagnosis of onychomycosis. Colour contrast provided by the CSB made it easier identification of fungal elements.

Introduction: Periorbital hyperpigmentation (POH) is a routinely encountered condition in dermatology practice. Studying the clinical features and its correlation with dermoscopy will help in better understanding of patterns of periorbital pigmentation and its evolution. Methodology: Fifty patients attending dermatology outpatient department with POH as presenting complaint were included in the study. A detailed history and proper clinical examination were done. Laboratory tests were advised whenever necessary. Dermoscopy of pigmentation over both lower eyelids was done with ×200 magnification of Oitez e-scope (DP-M17 filter e-scope pro [optical ×200]). Clinical photographs of all patients were taken. Results: POH was multifactorial. The most common clinical type is postinflammatory type. Other associated clinical findings included pigmentation at other anatomical sites (20%), visible bulging (10%), tear trough (8%), and visible superficial vessels in the periorbital region (6%). On dermoscopy, majority of the patients had multicomponent pattern (64%) which included more than one pattern of pigmentation, vasculature, and skin changes. The different patterns of pigmentation were blotches (30%), exaggerated pigment network (28%), coarse speckled (24%), fine speckled (20%), and globules (16%). Pattern of vasculature included telangiectases (18%) and superficial dilated vessels (20%). Patterns of skin changes included atrophy (18%) and exaggerated skin markings (22%). Dermoscopic features can correlate with its etiology. Conclusion: POH is a multifactorial entity. Dermoscopic features can correlate with its etiology.

Eccrine syringofibroadenoma (ESFA) is a rare, benign tumor showing acrosyringeal or sweat gland differentiation with variable clinical presentations, but distinct histopathological features. Rarely, ESFA coexists with a malignancy such as a squamous cell carcinoma or porocarcinoma. Herein, we report the first case of an ESFA associated with a verrucous carcinoma in a 46-year-old female on the right foot. It is unclear whether it represents a reactive process, a malignant transformation or a collision tumor. We recommend ESFA be completely excised if possible or closely followed given its association with a developing carcinoma.

Annular elastolytic giant cell granuloma is a rare granulomatous disease with unknown pathogenesis. It clinically presents as single or multiple well-defined erythematous annular arciform serpiginous polycyclic plaque with indurated elevated borders and central atrophy in sun-exposed areas. It is found to have a causal association with conditions such as diabetes mellitus, T-cell leukemia, CD4 lymphoma, cutaneous amyloidosis, squamous cell carcinoma lung, sarcoidosis, and monoclonal gammopathy. On histopathology, characteristic “elastophagocytosis” of dermal elastic fibers by the multinucleated giant cells is seen. The presence of horizontally oriented fragmented elastic fibers is characteristic. There is no necrobiosis or mucin deposition, thus differentiating from granuloma annulare. We herein report a case of elderly male with type 2 diabetes mellitus who presented with asymptomatic multiple discrete erythematous shiny dome-shaped papules over anterior chest, abdomen, and back of 2-month duration. The diagnosis was confirmed by biopsy and thorough workup for associations was done. This case is reported due to the rarity of the disease, the atypical presentation, and the characteristic histopathology which lead to the diagnosis.

Skin metastases are relatively rare but are of important clinical significance because they usually indicate a worse prognosis. The most common sources are lung and colorectal cancers in males and breast and colorectal in females. In this report, we presented a chest wall skin metastasis of gastric origin in a 50-year-old male. Tumor metastasis to unusual locations such as chest wall skin and from unusual origins such as stomach is of great clinical importance.

Sarcoid reactions are noncaseating granulomas that simulate sarcoidosis. Since they do not fulfill the rest of criteria to diagnose systemic sarcoidosis, they have a separate identity. They are often reported in draining lymph nodes of malignancies. However, they can also occur in the skin forming “Cutaneous sarcoid reaction” – such as this case. We report the case of a 17-year-old female with itchy, papules persistent for 3 months while she had no other complaint. The papules were present on the trunk and lower extremities. General examination was unremarkable except for cervical lymphadenopathy. Bone marrow aspirate and biopsy revealed features of “acute lymphoblastic leukemia (ALL)”. As the peripheral blood smear showed no blasts, it was hard to diagnose her leukemia. Skin biopsy showed features of granulomatous reaction simulating sarcoidosis. Her final diagnosis was compatible with “aleukemia form of ALL”. The patient was started on chemotherapy and her itching was relieved with treatment. The skin papules were resolved leaving behind hyperpigmentation. The link between sarcoidal reactions and malignancies still needs further research. However, cutaneous sarcoidal reactions may be the first presentation of systemic malignancy. Patients presenting with sarcoidal reactions should be investigated to exclude the associated malignancy.

The umbilicus is an uncommon site of cutaneous metastasis called as Sister Mary Joseph's nodule (SMJN), which is associated with grave prognosis. The most common primaries are the colon and stomach in males and ovaries and endometrium in females. We present a case of an elderly male with indurated umbilical swelling, unguided fine-needle aspiration cytology (FNAC) of which revealed umbilical metastasis (SMJN). On subsequent extensive work-up, this case was diagnosed as primary gastric adenocarcinoma on relevant gastric biopsy. This highlights the cost-effectiveness, time-saving diagnosis with the usage of FNAC procedure in such umbilical nodule cases, which are later confirmed on histopathology.

Papular acantholytic dyskeratosis (PAD) is a challenging diagnosis for both dermatologist and pathologist. It predominantly affects female patients, but men can present less frequently the disease. Histopathology is required to confirm the diagnosis and to exclude other acantholytic dermatoses. We present a rare case of PAD in a young male patient, diagnosed by histopathology, and responded well to oral retinoids.

Spiradenocylindroma is a rare occurrence where tumor has histological features of both spiradenoma and cylindroma in single nodular lesion. Due to dual histomorphological features in a single lesion, it is considered as a hybrid tumor. We describe a case of spiradenocylindroma in a 70-year old female. Spiradenocylindroma presents a diagnostic challenge to the histopathologist because both tumors share some common features; however, the presence and absence of lymphocytes are important for differentiation.

We report the case of a 60-year-old male presented with axillary swelling of 18 months duration with ulceration and cervical lymphadenopathy of 3 months duration with a clinical diagnosis of scrofuloderma. Histopathology showed dermis infiltrated by sheets, nests, and clusters of polygonal cells with markedly pleomorphic mitotically active nuclei suggestive of a more sinister condition, poorly differentiated cutaneous adenocarcinoma either primary or metastasis from breast. The condition is reported for its rarity from male breast and the need to consider it as a differential diagnosis in similar clinical presentation.